1,092 research outputs found
Serial optical coherence microscopy for label-free volumetric histopathology
The observation of histopathology using optical microscope is an essential procedure for examination of tissue biopsies or surgically excised specimens in biological and clinical laboratories. However, slide-based microscopic pathology is not suitable for visualizing the large-scale tissue and native 3D organ structure due to its sampling limitation and shallow imaging depth. Here, we demonstrate serial optical coherence microscopy (SOCM) technique that offers label-free, high-throughput, and large-volume imaging of ex vivo mouse organs. A 3D histopathology of whole mouse brain and kidney including blood vessel structure is reconstructed by deep tissue optical imaging in serial sectioning techniques. Our results demonstrate that SOCM has unique advantages as it can visualize both native 3D structures and quantitative regional volume without introduction of any contrast agents
Cost-Effectiveness of Haemorrhoidal Artery Ligation versus Rubber Band Ligation for the Treatment of Grade II–III Haemorrhoids: Analysis Using Evidence from the HubBLe Trial
Aim Haemorrhoids are a common condition, with nearly
30,000 procedures carried out in England in 2014/15, and
result in a significant quality-of-life burden to patients and
a financial burden to the healthcare system. This study
examined the cost effectiveness of haemorrhoidal artery
ligation (HAL) compared with rubber band ligation (RBL)
in the treatment of grade II–III haemorrhoids.
Method This analyses used data from the HubBLe study, a
multicentre, open-label, parallel group, randomised controlled
trial conducted in 17 acute UK hospitals between
September 2012 and August 2015. A full economic evaluation,
including long-term cost effectiveness, was conducted
from the UK National Health Service (NHS)
perspective. Main outcomes included healthcare costs,
quality-adjusted life-years (QALYs) and recurrence. Costeffectiveness
results were presented in terms of incremental
cost per QALY gained and cost per recurrence
avoided. Extrapolation analysis for 3 years beyond the trial
follow-up, two subgroup analyses (by grade of haemorrhoids
and recurrence following RBL at baseline), and
various sensitivity analyses were undertaken.
Results In the primary base-case within-trial analysis, the
incremental total mean cost per patient for HAL compared
with RBL was £1027 (95% confidence interval [CI] £782–
£1272, p\0.001). The incremental QALYs were 0.01
QALYs (95% CI -0.02 to 0.04, p = 0.49). This generated
an incremental cost-effectiveness ratio (ICER) of £104,427
per QALY. In the extrapolation analysis, the estimated
probabilistic ICER was £21,798 per QALY. Results from
all subgroup and sensitivity analyses did not materially
change the base-case result.
Conclusions Under all assessed scenarios, the HAL procedure
was not cost effective compared with RBL for the
treatment of grade II-III haemorrhoids at a cost-effectiveness
threshold of £20,000 per QALY; therefore
Towards green aviation with Python at petascale
Accurate simulation of unsteady turbulent flow is critical for improved design of greener aircraft that are quieter and more fuel-efficient. We demonstrate application of PyFR, a Python based computational fluid dynamics solver, to petascale simulation of such flow problems. Rationale behind algorithmic choices, which offer increased levels of accuracy and enable sustained computation at up to 58% of peak DP-FLOP/s on unstruc- tured grids, will be discussed in the context of modern hardware. A range of software innovations will also be detailed, including use of runtime code generation, which enables PyFR to efficiently target multiple platforms, including heterogeneous systems, via a single implemen- tation. Finally, results will be presented from a full- scale simulation of flow over a low-pressure turbine blade cascade, along with weak/strong scaling statistics from the Piz Daint and Titan supercomputers, and performance data demonstrating sustained computation at up to 13.7 DP-PFLOP/s
The conserved C-terminus of the PcrA/UvrD helicase interacts directly with RNA polymerase
Copyright: © 2013 Gwynn et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was supported by a Wellcome Trust project grant to MD (Reference: 077368), an ERC starting grant to MD (Acronym: SM-DNA-REPAIR) and a BBSRC project grant to PM, NS and MD (Reference: BB/I003142/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Holographic c-theorems in arbitrary dimensions
We re-examine holographic versions of the c-theorem and entanglement entropy
in the context of higher curvature gravity and the AdS/CFT correspondence. We
select the gravity theories by tuning the gravitational couplings to eliminate
non-unitary operators in the boundary theory and demonstrate that all of these
theories obey a holographic c-theorem. In cases where the dual CFT is
even-dimensional, we show that the quantity that flows is the central charge
associated with the A-type trace anomaly. Here, unlike in conventional
holographic constructions with Einstein gravity, we are able to distinguish
this quantity from other central charges or the leading coefficient in the
entropy density of a thermal bath. In general, we are also able to identify
this quantity with the coefficient of a universal contribution to the
entanglement entropy in a particular construction. Our results suggest that
these coefficients appearing in entanglement entropy play the role of central
charges in odd-dimensional CFT's. We conjecture a new c-theorem on the space of
odd-dimensional field theories, which extends Cardy's proposal for even
dimensions. Beyond holography, we were able to show that for any
even-dimensional CFT, the universal coefficient appearing the entanglement
entropy which we calculate is precisely the A-type central charge.Comment: 62 pages, 4 figures, few typo's correcte
A DNA-based method for studying root responses to drought in field-grown wheat genotypes
Root systems are critical for water and nutrient acquisition by crops. Current methods measuring root biomass and length are slow and labour-intensive for studying root responses to environmental stresses in the field. Here, we report the development of a method that measures changes in the root DNA concentration in soil and detects root responses to drought in controlled environment and field trials. To allow comparison of soil DNA concentrations from different wheat genotypes, we also developed a procedure for correcting genotypic differences in the copy number of the target DNA sequence. The new method eliminates the need for separation of roots from soil and permits large-scale phenotyping of root responses to drought or other environmental and disease stresses in the field.Chun Y. Huang, Haydn Kuchel, James Edwards, Sharla Hall, Boris Parent, Paul Eckermann, Herdina, Diana M. Hartley, Peter Langridge & Alan C. McKa
Having a lot of a good thing: multiple important group memberships as a source of self-esteem.
Copyright: © 2015 Jetten et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedMembership in important social groups can promote a positive identity. We propose and test an identity resource model in which personal self-esteem is boosted by membership in additional important social groups. Belonging to multiple important group memberships predicts personal self-esteem in children (Study 1a), older adults (Study 1b), and former residents of a homeless shelter (Study 1c). Study 2 shows that the effects of multiple important group memberships on personal self-esteem are not reducible to number of interpersonal ties. Studies 3a and 3b provide longitudinal evidence that multiple important group memberships predict personal self-esteem over time. Studies 4 and 5 show that collective self-esteem mediates this effect, suggesting that membership in multiple important groups boosts personal self-esteem because people take pride in, and derive meaning from, important group memberships. Discussion focuses on when and why important group memberships act as a social resource that fuels personal self-esteem.This study was supported by 1. Australian Research Council Future Fellowship (FT110100238) awarded to Jolanda Jetten (see http://www.arc.gov.au) 2. Australian Research Council Linkage Grant (LP110200437) to Jolanda Jetten and Genevieve Dingle (see http://www.arc.gov.au) 3. support from the Canadian Institute for Advanced Research Social Interactions, Identity and Well-Being Program to Nyla Branscombe, S. Alexander Haslam, and Catherine Haslam (see http://www.cifar.ca)
Assessing the clinical utility of cancer genomic and proteomic data across tumor types
Molecular profiling of tumors promises to advance the clinical management of cancer, but the benefits of integrating molecular data with traditional clinical variables have not been systematically studied. Here we retrospectively predict patient survival using diverse molecular data (somatic copy-number alteration, DNA methylation and mRNA, miRNA and protein expression) from 953 samples of four cancer types from The Cancer Genome Atlas project. We found that incorporating molecular data with clinical variables yielded statistically significantly improved predictions (FDR < 0.05) for three cancers but those quantitative gains were limited (2.2–23.9%). Additional analyses revealed little predictive power across tumor types except for one case. In clinically relevant genes, we identified 10,281 somatic alterations across 12 cancer types in 2,928 of 3,277 patients (89.4%), many of which would not be revealed in single-tumor analyses. Our study provides a starting point and resources, including an open-access model evaluation platform, for building reliable prognostic and therapeutic strategies that incorporate molecular data
PIK3CA dependence and sensitivity to therapeutic targeting in urothelial carcinoma
Background
Many urothelial carcinomas (UC) contain activating PIK3CA mutations. In telomerase-immortalized normal urothelial cells (TERT-NHUC), ectopic expression of mutant PIK3CA induces PI3K pathway activation, cell proliferation and cell migration. However, it is not clear whether advanced UC tumors are PIK3CA-dependent and whether PI3K pathway inhibition is a good therapeutic option in such cases.
Methods
We used retrovirus-mediated delivery of shRNA to knock down mutant PIK3CA in UC cell lines and assessed effects on pathway activation, cell proliferation, migration and tumorigenicity. The effect of the class I PI3K inhibitor GDC-0941 was assessed in a panel of UC cell lines with a range of known molecular alterations in the PI3K pathway.
Results
Specific knockdown of PIK3CA inhibited proliferation, migration, anchorage-independent growth and in vivo tumor growth of cells with PIK3CA mutations. Sensitivity to GDC-0941 was dependent on hotspot PIK3CA mutation status. Cells with rare PIK3CA mutations and co-occurring TSC1 or PTEN mutations were less sensitive. Furthermore, downstream PI3K pathway alterations in TSC1 or PTEN or co-occurring AKT1 and RAS gene mutations were associated with GDC-0941 resistance.
Conclusions
Mutant PIK3CA is a potent oncogenic driver in many UC cell lines and may represent a valuable therapeutic target in advanced bladder cancer
Consensus Analysis of Whole Transcriptome Profiles from Two Breast Cancer Patient Cohorts Reveals Long Non-Coding RNAs Associated with Intrinsic Subtype and the Tumour Microenvironment.
Long non-coding RNAs (lncRNAs) are emerging as crucial regulators of cellular processes and diseases such as cancer; however, their functions remain poorly characterised. Several studies have demonstrated that lncRNAs are typically disease and tumour subtype specific, particularly in breast cancer where lncRNA expression alone is sufficient to discriminate samples based on hormone status and molecular intrinsic subtype. However, little attempt has been made to assess the reproducibility of lncRNA signatures across more than one dataset. In this work, we derive consensus lncRNA signatures indicative of breast cancer subtype based on two clinical RNA-Seq datasets: the Utah Breast Cancer Study and The Cancer Genome Atlas, through integration of differential expression and hypothesis-free clustering analyses. The most consistent signature is associated with breast cancers of the basal-like subtype, leading us to generate a putative set of six lncRNA basal-like breast cancer markers, at least two of which may have a role in cis-regulation of known poor prognosis markers. Through in silico functional characterization of individual signatures and integration of expression data from pre-clinical cancer models, we discover that discordance between signatures derived from different clinical cohorts can arise from the strong influence of non-cancerous cells in tumour samples. As a consequence, we identify nine lncRNAs putatively associated with breast cancer associated fibroblasts, or the immune response. Overall, our study establishes the confounding effects of tumour purity on lncRNA signature derivation, and generates several novel hypotheses on the role of lncRNAs in basal-like breast cancers and the tumour microenvironment
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